Air circulation control for refrigerator trucks



" Oct. 17, .1950 H.E.cH}R|s1-MAN I2,525,866

AIR CIRCULATION CONTROL FOR REFRIGERATOR TRUCKS Fild May e, .1949

Patented Oct. 17,` 1950 -AIR CIRCULATION CONTROL` F0112;` l i`lEtEFRGfERATOR; TRUCKS lHaroid EfChristman, San Jose, Calif;I

` Application May 6, 1949, `Serial -N o. 91,694

s ciaims. (craze-13o) This invention relates to improvements inaircirculation control for refrigerator trucks; n, The principal object ofthis invention is-to provide means for `the `use of a wet and a `dry`refrigerant for cooling` the interiors of trucks or other refrigeratingareas.

A further object of this invention is to provide means for controlling`the circulation of air through the truck over and through the wetrefrigerant, `thence through the dry refrigerant and into therefrigerating space, so as to complete the circuit of air movement and,at the same time, to prevent-anyback drafts from; oc-

curring should the `forced circulation normally employed cease tofunction. i nl A further object is to .provide control `means which areautomatic in operation,simple to install and which occupy a minimumamount of space in the truck. C i l 1 i A still further..` object is to`provide a construction which may be employed with the ordinaryrefrigeration equipment now in use in mariy refrigerating trucks. l

Other objects and advantages will be apparent during the course of thefollowing description.

*beingtransportedf My invention consists in refrigerantgfit.enables theoperatorto maintain `anyydesired temperature `in therefrigerated area,regardless of `normal outside-temperatures;

`and that, byproviding draftcontrolling bull;-

heads, reverse `circulation of `air isi prevented. When reversecirculation `does take place, as

has been common heretofore, a freezing ofl the commodity adjacent therefrigerant takes place, due to the `natural dropping of cold air.`

Referring to `the accompanying drawings wherein, forthe purposeofillustration, is shown .a preferred `embodiment of my invention, thenumeral` fdesignates Aan `ordinary tractor to which is attached atrailer EL This trailer has afninterior space "I, in which commoditiesare positioning in the i 1forward end of the` `trailer a' refrigeratingunit In the accompanying drawings forming a part of this specication andin which like numerals are employed to designate like parts throughoutthe same,

Fig. l is a side elevation of a truck` andltrailer having my inventionapplied thereto, a portion of the trailer 'being shownin cross section',

Fig. 2 is an enlarged detail cross-sectional View, taken on the line 2-2of Fig. 1 and looking in the direction of the arrows, and

Fig. 3 is `an enlarged fragmentary detail crosssectional view, taken onthe line 3-3 of Fig. 1.

In the shipping of commodities, it is often necessary to provide`refrigeration means in order that the product being shipped will notspoil in transit. Many types of refrigerants are used, such as dry ice,block ice, or crushed ice. The dry ice is often objectionable in that itproduces too low a temperature and will absorb and freeze much of themoisture in the refrigeration area, thus dehydrating the products beingtransported. Wet ice, such as frozen water, often provides too muchmoisture and causes spoilage, particularly mildewing. Further, crushedice has to be replaced very often, due to its rapid melting.

Applicant has found that a combination of dry ice and wet ice, togetherwith forced circulation, results in an ideal condition and that, bycontrolling the circulation of air through the 8, such as described inmy vco-pe'nding application,` Serial No. 745,917, filed May 5, 1947.

On each side of this unit` I form ice compartments 9 and II through theuse ofbulkheads I2 and I3 respectively, which extend from the floorlevel ofthe truck, substantially half-way toward the topvof the truck.Within these ice compartments` I place slatted grills, as shown at I4and I8, the purpose` of which', will be later seen.

`Mounted upon the top of the unit 8, isa

blower Il, for the purpose of circulating the air within the truck.

, It willbe noted that, spaced from the unit 8 andthe bulkheads IZandI3, is a bulkhead I8, which extends from the slatted floor I9 in thetruck, to a point spaced slightly from the top of the truck, which pointis above the top of the commodities being carried in the, truck. Thisprovides for air to blow across the entire top I of the truck from thefront end to the back end and to pass downwardly between the crates orother goods being carried, and then to re-circulate beneath the sla-ttedbottom.

The result of this construction is that, when my truck is loaded withcommodities as designated by the letter A, air, circulated by the fanI'I, will cause a circulation along the top of the truck and downwardlybetween the stacked commodities, thence through the slatted door,passing underneath the bottom of the bulkhead i8, thence upwardly overthe bulkheads I2 andv I3, thence downwardly through the wet ice in theice compartments 5l and II, thence downwardly through the slatted bottomand upwardly through the louvres B, formed in the bottom of the'unit 8,tobe re-circulated by the fan Il.

The suction of the fan II will cause the air to follow the course justenumerated from the bottom of the truck over and through the wet ice anddry ice compartments. v

Thermostats or manual control may be employed for turning on and off thefan I'I so that any desired temperature may be maintained within thetrailer.

When the fan II, ceases to operate, there will be no back drafts caused,for the reason that the bulkheads I2 and I3, will trap the cold airbeing given cfr" by the wet and dry ice, as the cold air cannot rise andpass over these bulkheads I2 and I3 and, therefore, cannot escape overthe bulkheads I2 and I3, to flow beneath the slatted floor I9. Were itnot for these bulkheads I2 and I3, the cold air, sinking, could spreadalong the bottom of the trailer and could cause a frosting or freezingof all of the commodities adjacent the floor line, with the resultantspoilagye.

With my arrangement, the moisture given off by the wet ice will, to alarge extent, crystallize on to the sides of the unit I5, thusmaterially cutting down the moisture content of the air beingcirculated, so that a damp condition will not exist and yet it willprovide enough humidity so as to eliminate the drying out of thecommodities, as-occurs with the use of dry ice only. This drying out ofthe commodities results in great loss, particularly in theV shrinkage ofcommodities which are sold by the pound, such as animal carcasses.

' 1t will thus be seen that my air circulation control for refrigeratortrucks will perform all the objects above set forth.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes relative to the material, size, shape and arrangement ofparts may be resorted to without departing from the spiritr of theinvention or the scope of the subjoined claims.

Having thus described my invention, I- claim:

1. Air circulating control means for vehicles comprising a coolingcompartment positioned in one end of the vehicle, a bulkhead spaced fromthe end of the vehicle and extending transversely of the side walls at apoint in juxtaposition to said cooling compartment, said bulkheadextending from the oor of the vehicle substantially halfeway of thevehicles height, a second bulkhead spaced from said first-mentionedbulk*- head, the lower end of said last-mentioned bulkhead being spacedfrom the iloor of the vehicle andextending to a point above the coolingcompartment and spaced from the top of the Vehicle, and air-circulatingmeans for exhausting air through said cooling 'compartment and into thestorage area. of said vehicle, to be circulated downwardly and beneathsaid last-mentioned bulkhead, thence upwardly between said bulkheads andthrough said kcooling compartment.

2. In combination with a vehicle having an enclosed storage area, ofmeans for supporting a commodity above the floor of said vehicle, abulkhead extending from said supporting means to a point adjacent andspaced from the top of said vehicle, a second bulkhead spaced from saidfirst-mentioned bulkhead and extending from the floor of said vehicle toa point substantially halfway to the top of said vehicle, andrefrigeration means positioned between said last-mentioned bulkhead andthe end of said vehicle, means for forcing air through saidrefrigerating means, said last-mentioned bulkhead preventing the flow ofcold air from said refrigerating compartment toward the area beneathsaid commodity-supporting means when said air circulating means isinoperative.

3. Air circulating control means for enclosed walled vehicles comprisinga cooling unit positioned in said vehicle and against one of the wallsthereof', a bulkhead extending between one side of said unit and one ofthe walls of said Vehicle,

` said bulkhead forming a compartment adjacent REFERENCES. CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Scheuer July 1l, 1939 Number

